I probably couldn’t pay you to see The Interrupters, Steve James and Alex Kotlowitz’s new documentary about the plague of violence in Chicago’s black neighborhoods and the few good folks who try to prevent its outbreak. Given that description, I needed some prodding from my editor to watch the movie, and that’s my job. For other potential viewers, including card-carrying liberals, the whole grinding tragedy of urban crime is so very 1960s, though it still entraps millions of Americans. Today, the United States has an African-American president from Chicago, and almost no interest in the plight of the people he tried to community-organize. It’s brutal but true: as most of the world has written off Africa — figuring that the continent’s poverty, disease and genocide are beyond fixing or, frankly, caring about — so most of America has written off the black ghettos. And who needs a documentary to remind us about what we insist on ignoring?

I couldn’t convince you to see The Interrupters, which is now playing in New York City and opens Aug. 12 in Chicago, but Ameena Matthews could. She can talk almost anyone into anything — and, on those mean streets, out of grabbing a gun and confronting a rival. A petite charisma machine in a Muslim head scarf, Matthews is a member of CeaseFire, the group of reformed criminals who intervene in disputes that threaten to turn toxic fast. Gary Slutkin, the organization’s founder and a professor of epidemiology at the University of Illinois at Chicago’s School of Public Health, argues that violence is “a learned behavior” and “an infectious disease” and calls his Interrupters “disease-control workers.” They’re like the minister who wanders into a Western shootout and implores the combatants to put down their guns — except that the Interrupters are nondenominational, and use street language that would singe a reverend’s ears. The company motto: “Stop. Killing. People.”

Matthews turns that command into charm, flattery, badgering and fiery rhetoric. She brings to The Interrupters what every terrific documentary needs: an out-of-nowhere personality with the same magnetic watchability as any Hollywood star. She understands how angry bravado can instantly escalate into mortal combat: “Sticks and stones may break my bones,” she warns, and “Words will get you killed.” Her job is to stanch the impulse in some kids to go, as she says, from “zero to rage in 30 seconds.” When one young man tells her he fights every day, she smiles and says, “You’re too handsome to do that.” A favorite figure in the hood, Matthews is a person even the criminal element wants to know and help. When she gets out of her car and realizes she left the keys inside, a half-dozen knowing kids volunteer to slip the car lock for her.

The Interrupters know what they’re up against; they used to live this walking death. “You’ve been taught all your life that you gotta stand up, no matter what happens,” says Tio Hardiman, the director of CeaseFire Illinois and a onetime street hustler. “Death before dishonor.” In neighborhoods that are, without exaggeration, war zones — more young people were killed in urban Chicago in 2008 than in Iraq — the police are irrelevant and mostly invisible. The sign on one housefront reads, “Come back with a warrant,” and the Interrupters have no warrant. They are armed only with the power of persuasion, which doesn’t always work: one CeaseFire intern, Joel Sanchez, was shot during a mediation. But sometimes they have soothing if not healing powers that can avert death. At other times, they can bring a shooter to contrition. Cobe Williams, one of the prime Interrupters, convinces a teenager named Li’l Mikey, fresh out of jail, to return to the barber shop he robbed at gunpoint and apologize to the victims. The ensuing embrace is the stuff of inspiring fiction, but it happens for real as you watch.

Scene after scene in the movie has the melodramatic crackle of some highly charged, heavily armed confrontation from The Wire. That’s because Kotlowitz, who wrote a New York Times magazine story about CeaseFire, and James, whose Hoop Dreams and Stevie are true-life dramas set in some of the same neighborhoods, spent a year accompanying the Interrupters and filming their interventions. Sadly, fatal flareups are the pulse of these neighborhoods. Everyone has a memory of a friend or loved one who was slaughtered. A girl named Vanessa relates a dream in which her dead brother picks her up from school: “And he ran to me and gave me a big hug. He told me, ‘I’m not dead, I’m still here with you.'” Another girl, maybe 10, doesn’t have the consolation of dreams. In an art class run by another Interrupter, Eddie Bocanegra, the girl says softly, “There was this one time when our neighbors got into a fight, and I don’t know what else happened but somebody started shooting. And… then…” She dissolves in silent tears.

Ameena Matthews invests much of her energy in trying to find the path for Caprysha, a young convict who has been absent from school because, her mentor says delicately, “She had some technical difficulties with L-A-W.” Matthews treats Caprysha with tough love, but emphasis on the love; she notes that “The hand that life dealt her — me too — they were all twos.” In Matthews’ case, the spellbinding salesmanship, as well as her early life in crime, was a birthright: her father, Jeff Fort, was a gang leader who first earned the nickname Angel because of his ability to resolve turf battles; he had so smooth a line of patter that he was accepted by the Chicago establishment and invited to Richard Nixon’s 1969 inauguration. In the ’70s he Islamified his Black P. Stones gang as El Rukn and, aiming to bring the revolution to the streets, schemed to buy arms from Libya. He was convicted of domestic terrorism and of another murder, which earned him a 155-year prison sentence under a “no human contact” order.

That’s quite a legacy for Matthews to channel and overcome. She applied Fort’s seductive eloquence and converted to non-violent Islam; today she is married to Sheikh Rasheed Matthews, a genial hiphop imam, and celebrates kids’ birthdays by applying “May Allah bless you” lyrics to the “Happy Birthday” song. And though the intensity of crisis intervention weighs on her — “I don’t even know why I’m doing this,” she says at one point; “I must be a glutton for punishment” — she can always rouse herself to rouse the faithful. Addressing one of the many teen funerals at which she is asked to speak, she tells the mourners, “I know we hurt, because we loved Duke. But we got a responsibility to bring up our community to be vibrant. Whatever it is that’s going on, cease the fire, call the truce.”

So don’t see The Interrupters out of some grudging civic duty. See it for the beautiful and horrifying people, for the despair and the against-all-odds uplift. Hardiman stresses that CeaseFire doesn’t talk religion but it does work to save lives. For ordinary moviegoers in search of an enthralling experience, that work and this film are heroically life-affirming.